gilbertite

English

Etymology

Gilbert +‎ -ite, after Davies Gilbert, British philosopher.

Noun

gilbertite (uncountable)

1. (mineralogy) A particular kind of muscovite.
   • 1836, Thomas Thomson, Outlines of Mineralogy, Geology, and Mineral Analysis‎^[1], page 235:

     The mass of gilbertite in the specimens in my possession, is mixed with dark purple fluor spar, and with specks of another mineral, which has the aspect of apatite.

   • 1905, Frederick William Rudler, A Handbook to a Collection of the Minerals of the British Islands‎^[2], page 27:

     A yellowish or greenish micaceous mineral, observed originally at Stenna Gwynn and since found in several china-stone districts in Cornwall, as at St. Austell and Breage, has been distinguished by the name of Gilbertite—a name given by Dr. Thomas Thomson, in compliment to Davies Gilbert, the "Cornish philosopher," who was, at one time President of the Royal Society (b. 1767, d. 1839.)

   • 2012, Robert W. Boyle, Gold: History and Genesis of Deposits‎^[3], page 108:

     […] contemporaneous with gold are gilbertite, leptochlorite, tourmaline, iron sulphides, feldspar, (rare) carbonates, and quartz; post gold minerals are quartz, zinc and lead sulphides, and many others of geophases K and L.